Add overscroll edge effect animations for Android.

content/browser/renderer_host/render_widget_host_view_android.cc

Index: content/browser/renderer_host/render_widget_host_view_android.cc
diff --git a/content/browser/renderer_host/render_widget_host_view_android.cc b/content/browser/renderer_host/render_widget_host_view_android.cc
index 98646946830ab8fced1f5222b622fcadd914189c..3cde87fc4740cc40b654c31e0956eaf2f9333ab4 100644
--- a/content/browser/renderer_host/render_widget_host_view_android.cc
+++ b/content/browser/renderer_host/render_widget_host_view_android.cc
@@ -18,6 +18,7 @@
 #include "cc/output/compositor_frame.h"
 #include "cc/output/compositor_frame_ack.h"
 #include "content/browser/android/content_view_core_impl.h"
+#include "content/browser/android/overscroll_glow.h"
 #include "content/browser/gpu/gpu_surface_tracker.h"
 #include "content/browser/renderer_host/compositor_impl_android.h"
 #include "content/browser/renderer_host/image_transport_factory_android.h"
@@ -75,7 +76,7 @@ RenderWidgetHostViewAndroid::RenderWidgetHostViewAndroid(
     RenderWidgetHostImpl* widget_host,
     ContentViewCoreImpl* content_view_core)
     : host_(widget_host),
-      is_layer_attached_(true),
+      are_layers_attached_(true),
       content_view_core_(NULL),
       ime_adapter_android_(this),
       cached_background_color_(SK_ColorWHITE),
@@ -98,6 +99,11 @@ RenderWidgetHostViewAndroid::RenderWidgetHostViewAndroid(
 
   layer_->SetContentsOpaque(true);
 
+  if (!CommandLine::ForCurrentProcess()->
+          HasSwitch(switches::kDisableOverscrollEdgeEffect)) {
+    overscroll_effect_ = OverscrollGlow::Create();
+  }
+
   host_->SetView(this);
   SetContentViewCore(content_view_core);
 }
@@ -292,6 +298,9 @@ void RenderWidgetHostViewAndroid::Blur() {
       host_->GetRoutingID(), "Unselect", ""));
   host_->SetInputMethodActive(false);
   host_->Blur();
+
+  if (overscroll_effect_)
+    overscroll_effect_->Finish();
 }
 
 bool RenderWidgetHostViewAndroid::HasFocus() const {
@@ -307,28 +316,26 @@ bool RenderWidgetHostViewAndroid::IsSurfaceAvailableForCopy() const {
 }
 
 void RenderWidgetHostViewAndroid::Show() {
-  if (is_layer_attached_)
+  if (are_layers_attached_)
     return;
 
-  is_layer_attached_ = true;
-  if (content_view_core_)
-    content_view_core_->AttachLayer(layer_);
+  are_layers_attached_ = true;
+  AttachLayers();
 }
 
 void RenderWidgetHostViewAndroid::Hide() {
-  if (!is_layer_attached_)
+  if (!are_layers_attached_)
     return;
 
-  is_layer_attached_ = false;
-  if (content_view_core_)
-    content_view_core_->RemoveLayer(layer_);
+  are_layers_attached_ = false;
+  RemoveLayers();
 }
 
 bool RenderWidgetHostViewAndroid::IsShowing() {
   // ContentViewCoreImpl represents the native side of the Java
   // ContentViewCore.  It being NULL means that it is not attached
   // to the View system yet, so we treat this RWHVA as hidden.
-  return is_layer_attached_ && content_view_core_;
+  return are_layers_attached_ && content_view_core_;
 }
 
 gfx::Rect RenderWidgetHostViewAndroid::GetViewBounds() const {
@@ -398,7 +405,8 @@ void RenderWidgetHostViewAndroid::OnDidChangeBodyBackgroundColor(
 }
 
 void RenderWidgetHostViewAndroid::SendVSync(base::TimeTicks frame_time) {
-  host_->Send(new ViewMsg_DidVSync(host_->GetRoutingID(), frame_time));
+  if (host_)
+    host_->Send(new ViewMsg_DidVSync(host_->GetRoutingID(), frame_time));
 }
 
 void RenderWidgetHostViewAndroid::OnSetVSyncNotificationEnabled(bool enabled) {
@@ -434,10 +442,8 @@ void RenderWidgetHostViewAndroid::RenderViewGone(
 }
 
 void RenderWidgetHostViewAndroid::Destroy() {
-  if (content_view_core_) {
-    content_view_core_->RemoveLayer(layer_);
-    content_view_core_ = NULL;
-  }
+  RemoveLayers();
+  content_view_core_ = NULL;
 
   // The RenderWidgetHost's destruction led here, so don't call it.
   host_ = NULL;
@@ -574,6 +580,8 @@ void RenderWidgetHostViewAndroid::ComputeContentsSize(
   content_size_in_layer_ =
       gfx::Size(texture_size_in_layer_.width() - offset.x(),
                 texture_size_in_layer_.height() - offset.y());
+  // Content size changes should be reflected in associated animation effects.
+  UpdateAnimationSize(frame);
 }
 
 void RenderWidgetHostViewAndroid::OnSwapCompositorFrame(
@@ -687,6 +695,52 @@ void RenderWidgetHostViewAndroid::BuffersSwapped(
     ack_callbacks_.push(ack_callback);
 }
 
+void RenderWidgetHostViewAndroid::AttachLayers() {
+  if (!content_view_core_)
+    return;
+
+  content_view_core_->AttachLayer(layer_);
+
+  if (overscroll_effect_)
+    content_view_core_->AttachLayer(overscroll_effect_->root_layer());
+}
+
+void RenderWidgetHostViewAndroid::RemoveLayers() {
+  if (!content_view_core_)
+    return;
+
+  if (overscroll_effect_)
+    content_view_core_->RemoveLayer(overscroll_effect_->root_layer());
+
+  content_view_core_->RemoveLayer(layer_);
+}
+
+bool RenderWidgetHostViewAndroid::Animate(base::TimeTicks frame_time) {
+  if (!overscroll_effect_ || !HasFocus())
+    return false;
+  return overscroll_effect_->Animate(frame_time);
+}
+
+void RenderWidgetHostViewAndroid::UpdateAnimationSize(
+    const cc::CompositorFrame* frame) {
+  if (!overscroll_effect_)
+    return;
+  // Disable edge effects for axes on which scrolling is impossible.
+  const cc::CompositorFrameMetadata& metadata = frame->metadata;
+  overscroll_effect_->set_horizontal_overscroll_enabled(
+      metadata.root_layer_size.width() != metadata.viewport_size.width());
+  overscroll_effect_->set_vertical_overscroll_enabled(
+      metadata.root_layer_size.height() != metadata.viewport_size.height());
+  overscroll_effect_->set_size(content_size_in_layer_);
+}
+
+void RenderWidgetHostViewAndroid::ScheduleAnimationIfNecessary() {
+  if (!content_view_core_)
+    return;
+  if (overscroll_effect_ && overscroll_effect_->IsActive())
+    content_view_core_->SetNeedsAnimate();
+}
+
 void RenderWidgetHostViewAndroid::AcceleratedSurfacePostSubBuffer(
     const GpuHostMsg_AcceleratedSurfacePostSubBuffer_Params& params,
     int gpu_host_id) {
@@ -869,16 +923,28 @@ SkColor RenderWidgetHostViewAndroid::GetCachedBackgroundColor() const {
   return cached_background_color_;
 }
 
+void RenderWidgetHostViewAndroid::OnOverscrolled(
+    gfx::Vector2dF accumulated_overscroll,
+    gfx::Vector2dF current_fling_velocity) {
+  if (!overscroll_effect_ || !HasFocus())
+    return;
+  overscroll_effect_->OnOverscrolled(base::TimeTicks::Now(),
+                                     accumulated_overscroll,
+                                     current_fling_velocity);
+  ScheduleAnimationIfNecessary();
+}
+
 void RenderWidgetHostViewAndroid::SetContentViewCore(
     ContentViewCoreImpl* content_view_core) {
   RunAckCallbacks();
 
-  if (content_view_core_ && is_layer_attached_)
-    content_view_core_->RemoveLayer(layer_);
+  if (are_layers_attached_)
+    RemoveLayers();
 
   content_view_core_ = content_view_core;
-  if (content_view_core_ && is_layer_attached_)
-    content_view_core_->AttachLayer(layer_);
+
+  if (are_layers_attached_)
+    AttachLayers();
 }
 
 void RenderWidgetHostViewAndroid::RunAckCallbacks() {